An upper level plume of Pacific moisture, a shallow layer of dry air near the surface and a vigorous upper level disturbance combined to produce a widespread area of wintry precipitation across the northern sections of the Four State Region. The precipitation began across east Texas late Monday night (4th and 5th) and overspread the rest of the region on Tuesday, February 5th. The temperature profile was just cold enough for the precipitation to fall mainly as snow north of a line from Pittsburg, TX to along the Louisiana and Arkansas border. South of this line, the precipitation fell as a very cold rain with only a brief period of snow or sleet observed as far south as the Interstate 20 corridor. Snow amounts ranged from a relatively narrow band of 1 to 3 inches (illustrated above) to a snow swath of 3 to 6 inches across southeast Oklahoma, southwest Arkansas and extreme northeast Texas. The heaviest snowfall fell over the Red River Valley of northeast Texas, southeast Oklahoma and southwest Arkansas where 6 to 9 inches of snow fell.